UW: Study design, instrument development, main responsible for manuscript writing, data analysis.AS: Study design, instrument development, manuscript preparation, supervision. KÅ: Study design, data analysis, manuscript preparation, supervision. All auhtors read and approved the final manuscript.
The authors declare that they have no competing interests.
Arrhythmias can appear with a variety of symptoms, all from vague to pronounced and handicapping symptoms. Therefore, patient-reported outcomes (PROs) concerning symptom burden are important to assess and take into consideration in the care and treatment of patients with arrhythmias. The main purpose was to develop and validate a disease-specific questionnaire evaluating symptom burden in patients with different forms of arrhythmias.
A literature review was conducted and arrhythmia patients were interviewed. Identified symptoms were evaluated by an expert panel consisting of cardiologists and nurses working daily with arrhythmia patients. SF-36 and Symptoms Checklist (SCL) were used in the validation of the new questionnaire Arrhythmia-Specific questionnaire in Tachycardia and Arrhythmia (ASTA).
Homogeneity was evaluated with Spearman´s correlations and Cronbach´s alpha coefficient (α) was used to evaluate internal consistency. Construct validity was evaluated using item-total correlations and convergent and discriminant validity. For this, Spearman´s correlations were calculated between the ASTA symptom scale, SCL and SF-36. Concurrent validity was validated by Spearman´s correlations between the ASTA symptom scale and SCL.
The correlations between the different items in the ASTA symptom scale showed generally sufficient homogeneity. Cronbach´s coefficient was found to be satisfactory (α = 0.80; lower bound 95 % CI for α = 0.76). Construct validity was supported by item-total correlations where all items in the symptom scale were sufficiently correlated (≥0.3). Convergent and discriminant validity was supported by the higher correlations to the arrhythmia-specific SCL compared to the generic SF-36. Concurrent validity was evaluated and there were sufficiently, but not extremely strong correlations found between the ASTA symptom scale and SCL.
The nine items of the ASTA symptom scale were found to have good psychometric properties in patients with different forms of arrhythmias. Arrhythmia patients suffer from both frequent and disabling symptoms. The validated ASTA questionnaire can be an important contribution to PROs regarding symptom burden in arrhythmia patients.